Adds calls to disable regmap cache-only after a successful return from
cs35l56_wait_for_firmware_boot().

This is to prepare for a change in the shared ASoC module that will
leave regmap in cache-only mode after cs35l56_system_reset(). This is
to prevent register accesses going to the hardware while it is
rebooting.
Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Link: https://msgid.link/r/20240408101803.43183-3-rf@opensource.cirrus.comSigned-off-by: Mark Brown <broonie@kernel.org>